<?php
class Watermark extends Think{
var $input_image_file = "";        //输入图片的文件名
var $output_image_file = "";       //生成文件的名称
var $logo_image_name = "";         //包含存放路径的水印图片的文件名
var $logo_text = "";               //水印文字
var $logo_text_size = 18;          //水印文字大小
var $logo_text_angle = 4;          //水印文字角度
var $logo_text_pos = 6;            //水印文字放置位置
var $logo_text_font = "";          //水印文字的字体
var $logo_text_color = "#ffffff"; //水印字体的颜色值
var $logo_image_pos = 6;           //水印图片放置的位置
   //1 = 顶部居左，2 = 顶部居中，3 = 顶部居右，4 = 底部居左
   //5 = 底部居中，6 = 底部居右，7 = 中间居左，8 = 居中，9 = 中间居右
var $logo_image_transition = 25;   //水印图片与原图片的融合度(1=100)
var $jpeg_quality = 75;            //jpeg图片的质量
//生成水印图片
 function create($filename=""){
   if ($filename) $this->input_image_file = strtolower(trim($filename));
   $src_image_type = $this->get_type($this->input_image_file);
   $src_image = $this->createImage($src_image_type,$this->input_image_file);
   if (!$src_image) return;
   $src_image_w=imagesx($src_image);
   $src_image_h=imagesy($src_image);
   //开始处理水印logo图片信息，把两个图片合成为一个图片
   if ($this->logo_image_name){
    $this->logo_image_name = strtolower(trim($this->logo_image_name));
    $logo_image_type = $this->get_type($this->logo_image_name);
    $logo_image = $this->createImage($logo_image_type,$this->logo_image_name);
    $logo_image_w=imagesx($logo_image);
    $logo_image_h=imagesy($logo_image);
    $temp_logo_image = $this->getPos($src_image_w,$src_image_h,$this->logo_image_pos,$logo_image);
    $logo_image_x = $temp_logo_image["dest_x"];
    $logo_image_y = $temp_logo_image["dest_y"];
    imagecopymerge($src_image, $logo_image,$logo_image_x,$logo_image_y,0,0,$logo_image_w,$logo_image_h,$this->logo_image_transition);
   }
   //水印为纯文本
   if ($this->logo_text){
    $this->logo_text = $this->gb2utf8($this->logo_text);
    $temp_logo_text = $this->getPos($src_image_w,$src_image_h,$this->logo_text_pos);
    $logo_text_x = $temp_logo_text["dest_x"];
    $logo_text_y = $temp_logo_text["dest_y"];
    if(preg_match("/([a-f0-9][a-f0-9])([a-f0-9][a-f0-9])([a-f0-9][a-f0-9])/i", $this->logo_text_color, $color))
    {
     $red = hexdec($color[1]);
     $green = hexdec($color[2]);
     $blue = hexdec($color[3]);
     $logo_text_color = imagecolorallocate($src_image, $red,$green,$blue);
    }else{
     $logo_text_color = imagecolorallocate($src_image, 255,255,255);
    }
    //用TrueType字体向图像写入文本
    imagettftext($src_image,$this->logo_text_size,$this->logo_angle,$logo_text_x,$logo_text_y,$logo_text_color,$this->logo_text_font,$this->logo_text);
   }
   //保存生成的图片为新的文件
   if ($this->output_image_file){
    switch ($this->get_type($this->output_image_file)){
     case 'gif':$src_img=imagegif($src_image, $this->output_image_file); break;
     case 'jpeg':$src_img=imagejpeg($src_image, $this->output_image_file, $this->jpeg_quality); break;
     case 'png':$src_img=imagepng($src_image, $this->output_image_file); break;
     default:$src_img=imagejpeg($src_image, $this->output_image_file, $this->jpeg_quality); break;
    }
   }
   else
   { //在原来图片的基础上生成新的合成图片
    if ($src_image_type = "jpg") $src_image_type="jpeg";
    header("Content-type: image/{$src_image_type}");
    switch ($src_image_type){
     case 'gif':$src_img=imagepng($src_image); break;
     case 'jpg':$src_img=imagejpeg($src_image, "", $this->jpeg_quality);break;
     case 'png':$src_img=imagepng($src_image);break;
     default:$src_img=imagejpeg($src_image, "", $this->jpeg_quality);break;
    }
   }
   imagedestroy($src_image);
}
//根据文件名和类型创建图片
 function createImage($type,$img_name){
   if (!$type){
    $type = $this->get_type($img_name);
   }
   switch ($type){
    case 'gif':
     if (function_exists('imagecreatefromgif'))
    $tmp_img=@imagecreatefromgif($img_name);
     break;
    case 'jpg':
     $tmp_img=imagecreatefromjpeg($img_name);
     break;
    case 'png':
     $tmp_img=imagecreatefrompng($img_name);
     break;
    default:
     $tmp_img=imagecreatefromstring($img_name);
     break;
   }
   return $tmp_img;
}
//根据源图像的长、宽，位置代码，水印图片id来生成把水印放置到源图像中的位置
function getPos($sourcefile_width,$sourcefile_height,$pos,$logo_image=""){
   if ($logo_image){
    $insertfile_width = imagesx($logo_image);
    $insertfile_height = imagesy($logo_image);
   }else {
    $lineCount = explode("\r\n",$this->logo_text);
    $fontSize = imagettfbbox($this->logo_text_size,$this->logo_text_angle,$this->logo_text_font,$this->logo_text);
    $insertfile_width = $fontSize[2] - $fontSize[0];
    $insertfile_height = count($lineCount)*($fontSize[1] - $fontSize[3]);
   }
   switch ($pos){
    case 1://顶部居左
     $dest_x = 0;
     if ($this->logo_text){
      $dest_y = $insertfile_height;
     }else{
      $dest_y = 0;
     }
     break;
    case 2://顶部居中
     $dest_x = ( ( $sourcefile_width - $insertfile_width ) / 2 );
     if ($this->logo_text){
      $dest_y = $insertfile_height;
     }else{
      $dest_y = 0;
     }
     break;
    case 3://顶部居右
     $dest_x = $sourcefile_width - $insertfile_width;
     if ($this->logo_text){
      $dest_y = $insertfile_height;
     }else{
      $dest_y = 0;
     }
     break;
    case 4://底部居左
     $dest_x = 0;
     $dest_y = $sourcefile_height - $insertfile_height;
     break;
    case 5://底部居中
     $dest_x = ( ( $sourcefile_width - $insertfile_width ) / 2 );
     $dest_y = $sourcefile_height - $insertfile_height;
     break;
    case 6://底部居右
     $dest_x = $sourcefile_width - $insertfile_width;
     $dest_y = $sourcefile_height - $insertfile_height;
     break;
    case 7://中间居左
     $dest_x = 0;
     $dest_y = ( $sourcefile_height / 2 ) - ( $insertfile_height / 2 );
     break;
    case 8://居中
     $dest_x = ( $sourcefile_width / 2 ) - ( $insertfile_width / 2 );
     $dest_y = ( $sourcefile_height / 2 ) - ( $insertfile_height / 2 );
     break;
    case 9://中间居右
     $dest_x = $sourcefile_width - $insertfile_width;
     $dest_y = ( $sourcefile_height / 2 ) - ( $insertfile_height / 2 );
     break;
    default://底部居右
     $dest_x = $sourcefile_width - $insertfile_width;
     $dest_y = $sourcefile_height - $insertfile_height;
     break;
   }
   return array("dest_x"=>$dest_x,"dest_y"=>$dest_y);
}
//获取图片的格式，主要包括jpg,png和gif
function get_type($img_name){
   $name_array = explode(".",$img_name);
   if (preg_match("/\.(gif|jpg|jpeg|png)$/", $img_name, $matches)){
    $type = strtolower($matches[1]);
   }else{
    $type = "string";
   }
   return $type;
}
//指定的文字转换为UTF-8格式，使用gb2312保证中文的正常显示
function gb2utf8($gb){
   if(!trim($gb))
    return $gb;
   $filename="./gb2312.txt";
   $tmp=file($filename);
   $codetable=array();
   while(list($key,$value)=each($tmp))
    $codetable[hexdec(substr($value,0,6))]=substr($value,7,6);
   $utf8="";
   while($gb){
    if (ord(substr($gb,0,1))>127){
     $tthis=substr($gb,0,2);
     $gb=substr($gb,2,strlen($gb)-2);
     $utf8.=$this->u2utf8(hexdec($codetable[hexdec(bin2hex($tthis))-0x8080]));
    }else{
     $tthis=substr($gb,0,1);
     $gb=substr($gb,1,strlen($gb)-1);
     $utf8.=$this->u2utf8($tthis);
    }
   }
   return $utf8;
}
//转换为UTF8编码
function u2utf8($c){
   $str="";
   if ($c < 0x80){
    $str.=$c;
   }else if ($c < 0x800){
    $str.=chr(0xC0 | $c>>6);
    $str.=chr(0x80 | $c & 0x3F);
   }else if ($c < 0x10000){
    $str.=chr(0xE0 | $c>>12);
    $str.=chr(0x80 | $c>>6 & 0x3F);
    $str.=chr(0x80 | $c & 0x3F);
   }else if ($c < 0x200000){
    $str.=chr(0xF0 | $c>>18);
    $str.=chr(0x80 | $c>>12 & 0x3F);
    $str.=chr(0x80 | $c>>6 & 0x3F);
    $str.=chr(0x80 | $c & 0x3F);
   }
   return $str;
}
}
?>